^"14 CFR 241.04 - Air Carrier Groupings". Code of Federal Regulations (PDF). US Government Publishing Office. p. 113.
^Chadwick, Jr., William (December 15, 2023) [effective January 1, 2024]. Air Carrier Groupings 2024 (PDF). Accounting and Reporting Directive of the Office of Airline Information (Report). Vol. 338. Washington, D.C.: Bureau of Transportation Statistics, United States Department of Transportation. Retrieved January 25, 2024.
^Mazareanu, Elena (3 February 2023). "Domestic Market Share of Leading U.S. Airlines from January to December 2021". Statista. Archived from the original on 14 March 2023.